/* ----------------------------------------------------------------------
   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
   http://lammps.sandia.gov, Sandia National Laboratories
   Steve Plimpton, sjplimp@sandia.gov

   Copyright (2003) Sandia Corporation.  Under the terms of Contract
   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
   certain rights in this software.  This software is distributed under
   the GNU General Public License.

   See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */

#include "info.h"
#include "input.h"
#include "lammps.h"
#include "utils.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

#include <cstdio>
#include <mpi.h>
#include <string>

using namespace LAMMPS_NS;
using testing::StartsWith;
using testing::StrEq;
using utils::sfgets;
using utils::sfread;
using utils::split_words;

#define TEST_FAILURE(...)                \
    if (Info::has_exceptions()) {        \
        ASSERT_ANY_THROW({__VA_ARGS__}); \
    } else {                             \
        ASSERT_DEATH({__VA_ARGS__}, ""); \
    }

// whether to print verbose output (i.e. not capturing LAMMPS screen output).
bool verbose = false;

class FileOperationsTest : public ::testing::Test {
protected:
    LAMMPS *lmp;

    void SetUp() override
    {
        const char *args[] = {"FileOperationsTest", "-log", "none", "-echo", "screen", "-nocite"};
        char **argv        = (char **)args;
        int argc           = sizeof(args) / sizeof(char *);
        if (!verbose) ::testing::internal::CaptureStdout();
        lmp = new LAMMPS(argc, argv, MPI_COMM_WORLD);
        if (!verbose) ::testing::internal::GetCapturedStdout();
        ASSERT_NE(lmp, nullptr);
        FILE *fp = fopen("safe_file_read_test.txt", "wb");
        ASSERT_NE(fp, nullptr);
        fputs("one line\n", fp);
        fputs("two_lines\n", fp);
        fputs("\n", fp);
        fputs("no newline", fp);
        fclose(fp);
    }

    void TearDown() override
    {
        if (!verbose) ::testing::internal::CaptureStdout();
        delete lmp;
        if (!verbose) ::testing::internal::GetCapturedStdout();
        remove("safe_file_read_test.txt");
    }
};

#define MAX_BUF_SIZE 128
TEST_F(FileOperationsTest, safe_fgets)
{
    char buf[MAX_BUF_SIZE];

    FILE *fp = fopen("safe_file_read_test.txt", "r");
    ASSERT_NE(fp, nullptr);

    memset(buf, 0, MAX_BUF_SIZE);
    utils::sfgets(FLERR, buf, MAX_BUF_SIZE, fp, "safe_file_read_test.txt", lmp->error);
    ASSERT_THAT(buf, StrEq("one line\n"));

    memset(buf, 0, MAX_BUF_SIZE);
    utils::sfgets(FLERR, buf, MAX_BUF_SIZE, fp, "safe_file_read_test.txt", lmp->error);
    ASSERT_THAT(buf, StrEq("two_lines\n"));

    memset(buf, 0, MAX_BUF_SIZE);
    utils::sfgets(FLERR, buf, MAX_BUF_SIZE, fp, "safe_file_read_test.txt", lmp->error);
    ASSERT_THAT(buf, StrEq("\n"));

    memset(buf, 0, MAX_BUF_SIZE);
    utils::sfgets(FLERR, buf, 4, fp, "safe_file_read_test.txt", lmp->error);
    ASSERT_THAT(buf, StrEq("no "));

    memset(buf, 0, MAX_BUF_SIZE);
    utils::sfgets(FLERR, buf, MAX_BUF_SIZE, fp, "safe_file_read_test.txt", lmp->error);
    ASSERT_THAT(buf, StrEq("newline"));

    memset(buf, 0, MAX_BUF_SIZE);
    ::testing::internal::CaptureStdout();
    TEST_FAILURE(
        utils::sfgets(FLERR, buf, MAX_BUF_SIZE, fp, "safe_file_read_test.txt", lmp->error););
    auto mesg = ::testing::internal::GetCapturedStdout();
    ASSERT_THAT(mesg, StartsWith("ERROR on proc 0: Unexpected end of file while "
                                 "reading file 'safe_file_read_test.txt'"));

    fclose(fp);
}

#define MAX_BUF_SIZE 128
TEST_F(FileOperationsTest, safe_fread)
{
    char buf[MAX_BUF_SIZE];

    FILE *fp = fopen("safe_file_read_test.txt", "r");
    ASSERT_NE(fp, nullptr);

    memset(buf, 0, MAX_BUF_SIZE);
    utils::sfread(FLERR, buf, 1, 9, fp, "safe_file_read_test.txt", lmp->error);
    ASSERT_THAT(buf, StrEq("one line\n"));

    memset(buf, 0, MAX_BUF_SIZE);
    utils::sfread(FLERR, buf, 1, 10, fp, "safe_file_read_test.txt", nullptr);
    ASSERT_THAT(buf, StrEq("two_lines\n"));

    ::testing::internal::CaptureStdout();
    TEST_FAILURE(utils::sfread(FLERR, buf, 1, 100, fp, "safe_file_read_test.txt", lmp->error););
    auto mesg = ::testing::internal::GetCapturedStdout();
    ASSERT_THAT(mesg, StartsWith("ERROR on proc 0: Unexpected end of file while "
                                 "reading file 'safe_file_read_test.txt'"));

    // short read but no error triggered due to passing a NULL pointer
    memset(buf, 0, MAX_BUF_SIZE);
    clearerr(fp);
    rewind(fp);
    utils::sfread(FLERR, buf, 1, 100, fp, "safe_file_read_test.txt", nullptr);
    ASSERT_THAT(buf, StrEq("one line\ntwo_lines\n\nno newline"));
    fclose(fp);
}

TEST_F(FileOperationsTest, logmesg)
{
    char buf[8];
    ::testing::internal::CaptureStdout();
    lmp->input->one("echo none");
    ::testing::internal::GetCapturedStdout();
    ::testing::internal::CaptureStdout();
    utils::logmesg(lmp, "one\n");
    lmp->input->one("log test_logmesg.log");
    utils::logmesg(lmp, "two\n");
    lmp->input->one("log none");
    std::string out = ::testing::internal::GetCapturedStdout();
    memset(buf, 0, 8);
    FILE *fp = fopen("test_logmesg.log", "r");
    fread(buf, 1, 8, fp);
    fclose(fp);
    ASSERT_THAT(out, StrEq("one\ntwo\n"));
    ASSERT_THAT(buf, StrEq("two\n"));
    remove("test_logmesg.log");
}

int main(int argc, char **argv)
{
    MPI_Init(&argc, &argv);
    ::testing::InitGoogleMock(&argc, argv);

    // handle arguments passed via environment variable
    if (const char *var = getenv("TEST_ARGS")) {
        std::vector<std::string> env = split_words(var);
        for (auto arg : env) {
            if (arg == "-v") {
                verbose = true;
            }
        }
    }

    if ((argc > 1) && (strcmp(argv[1], "-v") == 0)) verbose = true;

    int rv = RUN_ALL_TESTS();
    MPI_Finalize();
    return rv;
}